This invention relates to apparatus for handling tubular articles such as cigarettes, tubular cigarette components, spiral wound paper and/or foil tubes, etc., and more particularly to apparatus for holding or guiding such articles parallel to their length.
There are many instances in tube making or handling where a tube must be held or guided parallel to its length. For example, in the typical cigarette making machine, the tobacco rod is initially formed as a continuous tobacco-filled paper tube which moves continuously parallel to its length as it is made. The end portion of this tube is periodically cut off to form cut lengths of tube (e.g., by a conventional Molins Mark VIII cutter head available from Molins of London, England). Each successive cut length is then accelerated parallel to its length (e.g., by the spiral spacer wheel in a conventional Molins Mark VIII cutter head) in order to place the cut length in the next successive flute on a fluted catcher drum which is rotating about an axis parallel to the longitudinal axis of the initial continuous rod. From that point on, the cut lengths tend to move transverse to their longitudinal axes (e.g., for such purposes as the addition of filters).
Between the point at which the cutter head cuts the tube and the point at which the spiral spacer wheel takes over control of the cut length in order to accelerate it into a catcher drum flute, the cut length of tube must be kept under control so that it remains in line--pushed along by the tube behind--but so that it can be freely accelerated once it reaches the spiral spacer wheel. The spiral spacer wheel also typically deflects the path of the tube slightly transverse to its longitudinal axis in order to facilitate insertion of the tube into the next catcher drum flute. The tube controlling elements must therefore not be so rigid or inflexible as to prevent this necessary tube deflection.
Heretofore the typical means for controlling the cut lengths of tube from the point at which they are cut to the point at which they come under control of the spiral spacer wheel have been spring fingers which resiliently press the tube against tube-supporting and guiding surfaces. Such spring fingers tend to be delicate, easily damaged when the machine jams or when a jam is being cleared, and difficult to adjust for optimum performance.
Although the foregoing shortcomings of the prior art have been described in the context of handling tobacco-filled rods, the same problems may be encountered in handling tubes of other kinds. For example, in making spiral wound tubes of paper and/or foil as shown, for example, in Meyer U.S. Pat. No. 4,473,368, it is sometimes necessary to guide the cut off lengths of tube in a manner similar to that described above, so that the above-mentioned shortcomings of the prior art are encountered again.
In view of the foregoing, it is an object of this invention to provide improved and simplified tube holding or guiding apparatus.
It is a more particular object of this invention to provide tube holding or guiding apparatus which is extremely reliable, robust, and easy to adjust.